The Bulgarian Football Union (BFU) has indefinitely suspended three players, including midfielder Steven Petkov from champions Ludogorets, over allegations of match-fixing.

The BFU said in a statement overnight that the allegations related to an ongoing investigation over attempts to manipulate Bulgaria matches at last month's Under-19 European Championship in Hungary.

Lokomotiv Sofia goalkeeper Daniel Gyaurov, who was held for 24 hours after he was arrested following a joint operation involving the interior ministry and the BFU last week, and his former team-mate Grigor Grigorov, have also been suspended.

Gyaurov has denied any wrongdoing after being released from custody at the weekend.

Bulgaria's Under-19 team lost their three games and finished bottom of Group B without scoring a goal at Euro 2014.

Ludogorets, who won the domestic league title three years in a row, reacted quickly by announcing that they sacked 19-year-old Petkov with immediate effect.

''In this situation, there's no way Steven Petkov to be our player,'' Ludogorets's chief executive Angel Petrichev told local media.

Petkov, considered one of the best young players in the Balkan country, did not play at the Euros after coach Alexander Dimitrov decided to omit him just before the team's departure to Hungary.